Could be a any one or more of a bunch of things -- light, water, fertilizer, soil. etc

Perhaps this pub will offer some insights
http://ir.library.oregonstate.edu/xmlui/bitstream/handle/1957/14210/ec1333.pdf

Here is a link that might be useful: Growing your own tomatoes

You said you planted it in FEB ?? and your plant is just 3ft tall ?? That is about 6 months ago !

1- where are you situated?
2- What variety (name ?) have you planted ?
3- what kind of potting mix did you use?
4) How often do you fertilize it ?

Finally, if you would post couple of pictures, it can be helpful for someone here to diagnose the problem.

What size pot do you have it in?

Also, normally you don't continue to repot a tomato during the growing season. You can pot up once or twice while it's a seedling, but when it's ready to plant outside you should put it in a pot big enough for the whole season. repotting during the growing season will set it back.

Can you post pictures?

My brother told me he had tomatoes in Dallas that he kept alive during the scorching months, and they didn't start to fruit until the weather cooled.

I've had the opposite situation, weather wise. I'm in northern MN. Our temps stayed in the 60's and 70's for most of July. As soon as the weather warmed, my plants began to really take off. Now they all have gorgeous fruit and some are still blooming.

This image is the best I can get at the moment. The plant usually sits on a window ledge where the sun gets its all day. I water it every few days and use tomato feed once a week. I'm not sure what kind it is as I was given them by an acquittance I am no longer in contact with. As you can see its starting to grow a bit wild. Lol.